NASAs IPoverSatellite Technology Development

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NASAs IP-over-Satellite Technology Development

• Andrew Z. Dowen
• Data Standards Program Office Mgr., NASA
• Robert C. Durst
• The MITRE Corporation

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Topics

• Briefing purpose
• Motivation
• Activities
• Results
• Issues
• Conclusions

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Briefing Purpose

• To review NASAs development activities related
  to the use of Internet technologies...
• For communication with a spacecraft (Mission
  Operations)
• For communication via a spacecraft (SATCOM)

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Background and Motivation

• Motivation for Internet communication with a
  spacecraft
• Hypothesis 1 Internet/Intranet interfaces to
  spacecraft will simplify spacecraft bus and
  payload development and test
• Hypothesis 2 Internet/Intranet access to
  spacecraft will reduce operations costs
• Hypothesis 3 Internet/Intranet access to
  spacecraft will improve the quality, quantity,
  and timeliness of science data

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Background and Motivation (Cont.)

• Motivation for Internet communication via
  spacecraft
• Satellite communications to remote regions
• Exploitation of broadcast technology
• NASA has been working to establish and optimize
  Internet communication with spacecraft and via
  spacecraft since 1992

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Activities

• Architectural alternatives
• Protocol development and tuning
• Commercial product development
• Commercial product integration
• Operations concept development
• Testing / Demonstrations

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Architectural AlternativeEnd-to-End Architecture
ES
ES
ES
ES
ES
ES
GS
GS
ES
ES
ES
ES
ES
ES
ES

• Distinguishing features
• End-to-end protocol operation at IP and above
• Application and transport connections run
  end-to-end
• Each transport (TCP) endpoint must be tuned to
  maximize performance/utilizationover satellite
  link
• Tunings for satellite link may be inappropriate
  for terrestrial links

ES
ES
ES
ES End System GS Ground Station
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Architectural AlternativeProxy-Based
Architecture
COTS
ES
ES
COTS
ES
ES
ES
GW
ES
GW
ES
Proxy Space
ES
ES
ES
ES
ES
ES

• Distinguishing features
• Dual-gateway (proxy) configuration
• ES transport connections do not cross the
  satellite/wireless link so ESs do not have to
  be satellite/wireless aware (e.g., can be
  unmodified COTS, simplifies deployment)
• Application layer connections run end-to-end
• Security above transport or via trusted gateways

ES
ES
ES
ES End System GW Transport Layer Gateway
(Proxy)
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Architectural AlternativeHybrid Proxy
Architecture
COTS
ES
ES
ES
ES
ES
GW
ES
ES
ES
ES
Proxy Space
ES

• Distinguishing features
• Single proxy gateway configuration
• ES connections on spacecraft/wireless side
  traverse the satellitehop - ESs must be
  satellite aware
• Wireless ES-to-ES communication via satellite
  possible without GWs
• Suitable for constellations or onboarduse

ES
ES
ES
ES End System GW Transport Layer Gateway
(Proxy)
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Activities Protocol Development and Tuning

• SCPS
• FTP and TCP extensions
• Security and network layer protocol definitions
• Performance enhancing proxies
• ACTS
• TCP tuning for end-to-end operation over high
  speed satellite channels
• Quality of Service
• Integrated Services to SC (RSVP extensions for
  TCP proxy gateways)

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Activities Commercial Product Development Support

• SCPS Reference Implementation
• End-system configuration
• TCP Performance Enhancing Proxy (PEP)
  configuration
• CISCO Mobile Router
• Enhancement to CISCOs Mobile IP software in a
  variety of their routers
• Consultative Committee for Space Data Systems
  (CCSDS) Device Driver for Linux
• CCSDS TC/TM over Ethernet / serial

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Activities COTS/GOTS Product Integration

• Custom IP Router-to-Satellite Modem interface box
  (Ground-Station Router Interface Device)
• Performs custom (not standard CCSDS/ISO)
  Reed-Solomon encoding/decoding of HDLC-framed
  space link traffic
• Linux PC/RS-422 to ITT/AES Low Power Transceiver
  (IP over HDLC)
• Onboard analog of above, to be flown as part of
  CANDOS experiment on STS-107
• Internet Key Exchange (IKE) integrated with SCPS
  TCP Performance Enhancing Proxies

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Activities Operations Concept Development

• FlatSAT activities defined notional operations
  concepts for Internet interaction with spacecraft
• Instrument to Command and Data Handling Subsystem
• Onboard storage to ground (telemetry)
• Mission Operations Center to Command and Data
  Handling
• Instrument commanding
• Spacecraft initiated communication

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Activities Testing and Demonstrations

• SATCOM Testing
• ACTS OC-12 (622 Mbps) satellite testbed for
  testing and tuning of high-speed
  Internet-over-satellite products
• SCPS SATCOM testing on M22 hosted by USAF Space
  and Missile Systems Command and over ACTS hosted
  by US Air Force Research Lab

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Results to date

• Standards
• ISO/CCSDS Space Link Extension service allows
  replacement of NASCOM custom 4800-bit block
  network with standard TCP/IP-based networks
  (underway)
• ISO/CCSDS/MIL standards for SCPS protocols and
  enhancements
• IETF Best Common Practice on TCP tuning (RFC 2488
  / BCP 28)

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Issues

• Benefits of Internet spacecraft operation over
  current practices need to be demonstrated/quantifi
  ed
• Reliance on automation may significantly reduce
  operations costs and increase flexibility
• Lights-out control centers
• Elimination of level zero processing

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Issues (Cont.)

• Cost saving resulting from change must offset ROI
  of incumbent approach with acceptable risk
• Is a below-IP hardware commanding capability
  (still) required? Not present on CHIPSAT
  present with IP over CCSDS TC/TM
• Acceptance will require/cause cultural change
• Operations concepts and architecture for
  end-to-end Internet-based mission operations have
  not been well-articulated or agreed to by the
  mission operations community

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Observations

• For communication with a satellite, to some
  extent, a technology looking for a need
• Consistent with NASA Code-Y Strategy to shift
  from technology derived from missions to
  missions enabled by technology

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Observations (Cont.)

• NASAs IP-in-space efforts have produced
  significant spin-off products
• Benefit to SATCOM and mobile/wireless industries
• Continued work with similar environments
  (SATCOM/mobile/wireless) can produce mature
  technologies for use when need arises

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Conclusions

• For communicating with a satellite, NASA has
  technology waiting for mission requirements and
  operations culture to evolve
• For communicating via a satellite, NASAs
  technology contribution has been considerable
• Is there a way for NASAs mainstream missions to
  benefit?

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Conclusions (Cont.)

• Feedback requested Is continued near-term
  investment in these technologies beneficial?
• Should NASA continue to spend its research money
  here?

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Support Slides
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Activities Protocol Development and Tuning
(Cont.)

• Mobile IP Extensions
• Registration acceleration (Ground station
  registers on behalf of all spacecraft endpoints)
• Mobile router -- Mobile IP registration of a
  subnet router
• Quality of Service
• Integrated Services to Spacecraft (RSVP
  extensions for TCP proxy gateways)

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Activities Testing and Demonstrations (Cont.)

• STRV 1b
• FTP/TCP/SCPS-TP testing on UK Defence Research
  Agency Satellite
• Mobile Router
• Field trial of mobile router using US Coast Guard
  ship, 802.11 and commercial satellite service

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Activities Testing and Demonstrations (Cont.)

• UoSAT-12
• Internet stack testing on Surrey Satellite,
  including NTP, FTP, UDP, multicast file transfer
  (MDP)
• CANDOS
• Shuttle payload to test Mobile IP to SC

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Results to date (Cont.)

• Products
• Refinements to commercial Internet
  implementations for satellite paths resulting
  from ACTS testing
• Open standard SCPS protocols and proxies
• Proprietary CISCO Mobile Router
• SkipWare and XipLink
• Interstellar Plasma Spectrometer mission (launch
  Dec 02)

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Results to date (Cont.)

• Mission(s)
• CHIPS/CHIPSat mission -- Internet-only spacecraft
  bus built by SpaceDev for UC-Berkeley Cosmic Hot

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Results to date (Cont.)
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Results to date (Cont.)